This invention concerns the positional stabilization of underground valves associated with buried gas and water pipes, and more particularly concerns apparatus which facilitates manipulative control of such valves by elongated devices which extend downwardly from ground level to engagement with the valve.
Pipelines that carry water and gas to residential and industrial buildings are generally located underground, usually at below-frostline depths of three to four feet. On-off control valves are generally positioned adjacent to the property line of each building served by the pipeline, said valves having an upwardly directed valve stem. A vertical conduit, usually of 4" to 8" diameter, and referred to as a "curb box" extends between the valve and the surface of the terrain to provide accessability to the valve. A horizontally disposed lid at the upper extremity of the curb box protects the conduit passageway.
The ground in which the valve sits is usually disturbed ground, namely ground which has been backfilled during the construction of the building or installation of the pipelines. Consequently, the valve is not held securely enough by the surrounding soil to support the valve and maintain the stem in perfectly upright orientation. Factors such as soil erosion, water infiltration, stresses imparted by the pipeline, and the downward force of the curb box or forces applied thereto contribute further to the insecure positioning of the valve. The possible dislocations of the valve include rolling movement around the pipe axis, tilting movement within the vertical plane of the pipe axis, twisting within the horizontal plane of the pipe axis caused by operating the valve stem, and vertical downward motion. For example, if a vehicle drives over the curb box lid, it can cause a poorly supported valve to be pushed downward to the extent of pinching off the pipeline. This is especially likely if the pipeline is fabricated of a plastic easily affected by deformational stresses.
The valve, generally referred to as a "curb cock" if it carries gas, is comprised of an elongated valve stem of circular cross-section vertically disposed within a housing provided with horizontally disposed round ports adapted to receive incoming and outgoing pipelines. The housing is generally downwardly tapered from an uppermost circular outer shoulder. The uppermost portion of the valve stem is provided with an engagement head having an elongated or square configuration. The lowermost extremity of the valve stem protrudes below the valve housing. To operate the valve in its on-off function, a long stemmed tool called a "key", and having an elongated or square slot or fork at its lowermost extremity, is lowered through the curb box to engage the head of the valve stem. The valve stem is then rotated about 90.degree. about its vertically disposed rotational axis.
If the valve stem is not perfectly upright, it cannot be engaged by the key. Even if the key engages the valve stem, rotation of the valve stem may not be achievable if the valve and adjacent pipe move when torque force is applied. In the case of plastic pipe, forceful twisting of the valve could crimp the pipe.
Various expedients have been disclosed for stabilizing the position of the aforesaid underground valves. Bricks, supporting pipes, and other materials and structures have been utilized in a bolstering manner. However, such expedients have generally provided buttressing support with respect to only one or two of the several modes of potential movement of the valve, and usually do not accommodate the access conduit.
It is accordingly an object of the present invention to provide a device for stabilizing an underground valve with respect to its several potential modes of movement.
It is another object of this invention to provide a device as in the foregoing object which engages the lower extremity of the curb box associated with said valve in centered relationship to said valve.
It is a further object of the present invention to provide an improved device of the aforesaid nature of simple and rugged construction which may be economically manufactured.
These objects and other objects and advantages of the invention will be apparent from the following description.